The Kremlin is unaware of any plans by fugitive former US spy agency contractor Edward Snowden to seek Russian citizenship, President Vladimir Putin's spokesman said today.

Snowden, who is wanted in the United States on espionage charges, is holed up at a Moscow airport. A Russian lawyer who helped him file an application for temporary asylum in Russia this week said Snowden had not ruled out seeking citizenship.

"Citizenship? This is the first I've heard of it. It's news to me," Putin spokesman Dmitry Peskov told reporters in the town of Novogorsk outside Moscow where Putin was meeting athletes.

Snowden's presence in the transit area of Moscow's Sheremetyevo airport since June 23 threatens to upset US-Russian relations.

But Peskov said the United States had not informed Russia of any plan by President Barack Obama to pull out of a summit with Putin in Moscow in September.

Since Snowden arrived at Sheremetyevo, the White House has deliberately left it vague as to whether Obama will go ahead the meeting in Moscow, which is to precede a summit of G20 leaders hosted by Putin in St Petersburg.